scholarly journals Ataxin-10 Inhibits TNF-α-Induced Endothelial Inflammation via Suppressing Interferon Regulatory Factor-1

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yong Li ◽  
Qi Zhang ◽  
Na Li ◽  
Liting Ding ◽  
Jinping Yi ◽  
...  

Endothelial inflammation is a crucial event in the initiation of atherosclerosis. Here, we identify Ataxin-10 protein as a novel negative modulator of endothelial activation by suppressing IRF-1 transcription activity. The protein level of Ataxin-10 is relatively higher in human vascular endothelial cells, which can be significantly suppressed by TNF-α in both HUVECs and HLMECs. Overexpression of Ataxin-10 markedly inhibited the mRNA expressions of VCAM-1 and several cytokines including MCP-1, CXCL-1, CCL-5, and TNF-α; thus, it can also suppress monocyte adhesion to endothelial cells. Accordingly, Ataxin-10 silencing promoted endothelial inflammation. However, Ataxin-10 did not affect the MAPK/NF-κB signaling pathway stimulated by TNF-α in HUVECs. Using the yeast two-hybrid assay, we found that Ataxin-10 can directly bind to interferon regulatory factor-1 (IRF-1). Upon TNF-α stimulation, Ataxin-10 promoted the cytoplasmic localization of IRF-1, which inhibited the transcription of VCAM-1. Moreover, knockdown of IRF-1 can eliminate the effect of Ataxin-10 on the expression of VCAM-1 in HUVECs induced by TNF-α. Taken together, these results indicate that Ataxin-10 inhibits endothelial cell activation and may serve as a promising therapeutic target for some vascular inflammatory-related diseases such as atherosclerosis.

2017 ◽  
Vol 9 (6) ◽  
pp. 546-560 ◽  
Author(s):  
Rui Yan ◽  
Matijs van Meurs ◽  
Eliane R. Popa ◽  
Rianne M. Jongman ◽  
Peter J. Zwiers ◽  
...  

Sepsis is a severe systemic inflammatory response to infection. Endothelial activation and dysfunction play a critical role in the pathophysiology of sepsis and represent an important therapeutic target to reduce sepsis mortality. Interferon regulatory factor 1 (IRF-1) was recently identified as a downstream target of TNF-α-mediated signal transduction in endothelial cells. The aim of this study was to explore the importance of IRF-1 as a regulator of lipopolysaccharide (LPS)-induced endothelial proinflammatory activation. We found that renal IRF-1 was upregulated by LPS in vivo as well as in LPS-stimulated endothelial cells in vitro. Furthermore, we identified intracellular retinoic acid inducible gene-I (RIG-I) as a regulator of LPS-mediated IRF-1 induction. IRF-1 depletion specifically resulted in diminished induction of VCAM-1 in response to LPS, but not of E-selectin or ICAM-1, which was independent of NFκB signaling. When both IRF-1 and the RIG-I adapter protein mitochondrial antiviral signaling (MAVS) were absent, VCAM-1 induction was not additionally inhibited, suggesting that MAVS and IRF-1 reside in the same signaling pathway. Surprisingly, E-selectin and IL-6 induction were no longer inhibited by MAVS knockdown when IRF-1 was also absent, revealing a redundant endothelial activation pathway. In summary, we report an IRF-1-mediated proinflammatory signaling pathway that specifically regulates LPS-mediated VCAM-1 expression, independent of NFκB.


2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Ting Wang

With the prevalence of antiviral therapy in the developed world, many HIV-1-infected people die of diseases other than AIDS. One of the emerging major causes is cardiovascular disease, leading to the prediction that the majority of HIV-1 patients are expected to develop cardiovascular complications. Endothelial dysfunction is thought to be a key event in the development of cardiovascular diseases, particularly atherosclerosis. Assays testing the effect of HIV-1 on endothelial activation shows that direct contact with HIV-1 infected T cells enhance endothelial cell activation to a greater extent than HIV-1 alone, suggesting an intracellular HIV-1 protein is responsible for endothelial activation. The HIV-1 viral protein Nef, which is responsible for T cell activation and maintenance of high viral loads in vivo , has been shown to mediate its own transfer to bystander cells. We demonstrate here for the first time that Nef induces nanotube-like conduits connecting T cells and endothelial cells. We also show that Nef is transferred from T cells to endothelial cells via these nanotubes, and is necessary and sufficient for endothelial cell activation. Moreover, we show that SIV-infected macaques exhibit endothelial Nef expression in coronary arteries. Nef expression in endothelial cells causes endothelial apoptosis, ROS and MCP-1 production. Interestingly, a Nef SH3 binding site mutant abolishes Nef-induced apoptosis and ROS formation and reduces MCP-1 production in endothelial cells, suggesting that the Nef SH3 binding site is critical for Nef effects on endothelial cells. Nef induces apoptosis of endothelial cells through an NADPH oxidase- and ROS-dependent mechanism, while Nef-induced MCP-1 production is NF-kB dependent. Taken together, these data suggest that Nef can mediate its transfer from T cells to endothelial cells through nanotubes to enhance endothelial dysfunction.Thus, Nef is a promising new therapeutic target for reducing the risk for cardiovascular disease in the HIV-1 positive population.


2002 ◽  
Vol 70 (3) ◽  
pp. 1352-1358 ◽  
Author(s):  
Catharina W. Wieland ◽  
Britta Siegmund ◽  
Giorgio Senaldi ◽  
Michael L. Vasil ◽  
Charles A. Dinarello ◽  
...  

ABSTRACT Chronic pulmonary infection with Pseudomonas aeruginosa is common in cystic fibrosis (CF) patients. P. aeruginosa lipopolysaccharide (LPS), phosholipase C (PLC), and exotoxin A (ETA) were evaluated for their ability to induce pulmonary inflammation in mice following intranasal inoculation. Both LPS and PLC induced high levels of tumor necrosis factor alpha (TNF-α), interleukin 1β (IL-1β), IL-6, gamma interferon (IFN-γ), MIP-1α and MIP-2 in the lungs but did not affect IL-18 levels. ETA did not induce TNF-α and was a weak inducer of IL-1β, IL-6, macrophage inflammatory protein 1α (MIP-1α), and MIP-2. Remarkably, ETA reduced constitutive lung IL-18 levels. LPS was the only factor inducing IFN-γ. LPS, PLC, and ETA all induced cell infiltration in the lungs. The role of interferon regulatory factor-1 (IRF-1) in pulmonary inflammation induced by LPS, PLC, and ETA was evaluated. When inoculated with LPS, IRF-1 gene knockout (IRF-1 KO) mice produced lower levels of TNF-α, IL-1β, and IFN-γ than did wild-type (WT) mice. Similarly, a milder effect of ETA on IL-1β and IL-18 was observed for IRF-1 KO than for WT mice. In contrast, the cytokine response to PLC did not differ between WT and IRF-1 KO mice. Accordingly, LPS and ETA, but not PLC, induced expression of IRF-1 mRNA. IRF-1 deficiency had no effect on MIP-1α and MIP-2 levels and on cell infiltration induced by LPS, PLC, or ETA. Flow cytometric evaluation of lung mononuclear cells revealed strongly reduced percentages of CD8+ and NK cells in IRF-1 KO mice compared to percentages observed for WT mice. These data indicate that different virulence factors from P. aeruginosa induce pulmonary inflammation in vivo and that IRF-1 is involved in some of the cytokine responses to LPS and ETA.


Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 708
Author(s):  
Ana María Rodríguez ◽  
Aldana Trotta ◽  
Agustina P. Melnyczajko ◽  
M. Cruz Miraglia ◽  
Kwang Sik Kim ◽  
...  

Central nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. A common feature associated with this pathology is blood–brain barrier (BBB) activation. However, the underlying mechanisms involved with such BBB activation remain unknown. The aim of this work was to investigate the role of Brucella abortus-stimulated platelets on human brain microvascular endothelial cell (HBMEC) activation. Platelets enhanced HBMEC activation in response to B. abortus infection. Furthermore, supernatants from B. abortus-stimulated platelets also activated brain endothelial cells, inducing increased secretion of IL-6, IL-8, CCL-2 as well as ICAM-1 and CD40 upregulation on HBMEC compared with supernatants from unstimulated platelets. Outer membrane protein 19, a B. abortus lipoprotein, recapitulated B. abortus-mediated activation of HBMECs by platelets. In addition, supernatants from B. abortus-activated platelets promoted transendothelial migration of neutrophils and monocytes. Finally, using a pharmacological inhibitor, we demonstrated that the Erk1/2 pathway is involved in the endothelial activation induced by B. abortus-stimulated platelets and also in transendothelial migration of neutrophils. These results describe a mechanism whereby B. abortus-stimulated platelets induce endothelial cell activation, promoting neutrophils and monocytes to traverse the BBB probably contributing to the inflammatory pathology of neurobrucellosis.


2005 ◽  
Vol 79 (16) ◽  
pp. 10442-10450 ◽  
Author(s):  
Victoria M. Wahl-Jensen ◽  
Tatiana A. Afanasieva ◽  
Jochen Seebach ◽  
Ute Ströher ◽  
Heinz Feldmann ◽  
...  

ABSTRACT Ebola virus causes severe hemorrhagic fever with high mortality rates in humans and nonhuman primates. Vascular instability and dysregulation are disease-decisive symptoms during severe infection. While the transmembrane glycoprotein GP1,2 has been shown to cause endothelial cell destruction, the role of the soluble glycoproteins in pathogenesis is largely unknown; however, they are hypothesized to be of biological relevance in terms of target cell activation and/or increase of endothelial permeability. Here we show that virus-like particles (VLPs) consisting of the Ebola virus matrix protein VP40 and GP1,2 were able to activate endothelial cells and induce a decrease in barrier function as determined by impedance spectroscopy and hydraulic conductivity measurements. In contrast, the soluble glycoproteins sGP and Δ-peptide did not activate endothelial cells or change the endothelial barrier function. The VLP-induced decrease in barrier function was further enhanced by the cytokine tumor necrosis factor alpha (TNF-α), which is known to induce a long-lasting decrease in endothelial cell barrier function and is hypothesized to play a key role in Ebola virus pathogenesis. Surprisingly, sGP, but not Δ-peptide, induced a recovery of endothelial barrier function following treatment with TNF-α. Our results demonstrate that Ebola virus GP1,2 in its particle-associated form mediates endothelial cell activation and a decrease in endothelial cell barrier function. Furthermore, sGP, the major soluble glycoprotein of Ebola virus, seems to possess an anti-inflammatory role by protecting the endothelial cell barrier function.


Blood ◽  
2002 ◽  
Vol 99 (2) ◽  
pp. 520-525 ◽  
Author(s):  
Andreas H. Wagner ◽  
Matthias Gebauer ◽  
Beatrix Pollok-Kopp ◽  
Markus Hecker

Abstract Given the significance of CD40–CD40 ligand interactions in chronic inflammatory diseases including atherosclerosis, the transcriptional regulation of CD40 expression as a potential therapeutic target was investigated in human umbilical vein cultured endothelial cells. Exposure to interferon-γ (IFN-γ) plus tumor necrosis factor-α resulted in a marked synergistic de novo expression of CD40, which, according to electrophoretic mobility shift analysis, was attributable to activation of the transcription factors nuclear factor-κB (NF-κB), signal transducer and activator of transcription-1 (STAT-1), and interferon regulatory factor-1 (IRF-1). Subsequent time-course studies revealed that de novo synthesis of IRF-1 preceded that of CD40. Decoy oligodeoxynucleotide (ODN) neutralization of STAT-1 or IRF-1, but not of NF-κB, inhibited cytokine-stimulated CD40 expression by 60% at both the mRNA and protein levels, and this effect was mimicked by antisense ODN blockade of IRF-1 synthesis. In contrast, CD40 expression in response to IFN-γ stimulation was sensitive to neutralization of STAT-1 only. These findings suggest that depending on the cytokine composition, CD40 expression in human endothelial cells under proinflammatory conditions is governed by STAT-1 either directly or indirectly through de novo synthesis of IRF-1. Moreover, decoy ODN neutralization of these transcription factors may provide a novel therapeutic option for interfering with CD40–CD40 ligand-mediated inflammatory responses in vivo.


2006 ◽  
Vol 101 (5) ◽  
pp. 1466-1473 ◽  
Author(s):  
Ginette S. Hoare ◽  
Emma J. Birks ◽  
Christopher Bowles ◽  
Nandor Marczin ◽  
Magdi H. Yacoub

Background: vascular endothelial cell activation and dysfunction are observed in patients with severe heart failure and may contribute to systemic manifestations of this syndrome. It remains unknown whether inflammatory activation of these cells occurs in these patients because of increased circulating proinflammatory mediators. Aim: to determine whether the serum from patients with heart failure possesses a net proinflammatory bioactivity to active proinflammatory pathways in cultured endothelial cells. Methods: serum was obtained from stable patients with end-stage heart failure undergoing elective cardiac transplantation (Tx) and severely decompensated patients with heart failure requiring emergency left ventricular assist device (LVAD) implantation. Net proinflammatory bioactivity of serum was investigated by monitoring IκBα degradation and E-selectin expression in cultured human pulmonary artery endothelial cells (HPAEC) following incubation with serum samples. Serum cytokine concentrations were measured by ELISA and neutralizing antibodies were used to determine the role of specific factors in the observed bioactivity. Result: serum from both patient groups induced HPAEC IκBα degradation. Low basal HPAEC E-selectin expression significantly increased following treatment with Tx but not LVAD serum. Serum tumor necrosis factor-α (TNF-α) and IL-10 concentrations were higher in patients with LVAD than those with Tx, and soluble TNF-α receptor expression was high in both groups. Neither TNF-α nor IL-10 blocking experiments altered either bioassay result. Conclusion: activation of a specific profile of pro- and anti-inflammatory mediators is associated with heart failure resulting in HPAEC nuclear factor (NF)-κB activation. However, E-selectin expression is further regulated by unidentified factors. TNF-α is upregulated but appears to play no part in NFκB activation in these patients. These findings could have important therapeutic implications.


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